This invention relates to a movable window unit comprising a window glass which can be lowered into a well of a panel member, as well as a motor control for an electric window-raising motor.
Practical examples are known of movable window units in the form of passenger car doors in which a window glass can be lowered into a well of a panel member. The window glass is guided in relation to the panel member by means of guide members and can be displaced by means of a motorized drive between an open end position and a closed end position. In order to guide the window glass, well seals are used in addition to three-dimensional guide rails which embrace the window glass at its side edges.
Practice has shown that, during the displacement of the window glass by means of the motorized drive, undesirable noises arise, depending upon the ambient temperature and the moisture on the glass in the region of the well seals. In order to eliminate these noises, well seals with surface coatings have been developed. In German Utility Model (Gebrauchsmuster) DE 295 15 597 U1 there has been described the phenomenon which supposedly causes this noise, which is referred to as the slip-stick effect. Additionally, in German Utility Model (Gebrauchsmuster) DE 295 15 597 U1, various overlays have been described for noise reduction during the displacement of the window glass.
It has been shown however that the known anti-squeaking overlays cannot prevent the generation of noise to the desired degree in all cases. It is therefore the object of the invention further to reduce the generation of noise during the displacement of a window glass of a movable window unit.
The invention concerns a window unit comprising a window glass which can be lowered into a well of a panel member, the window glass being guided relative to the panel member by means of guide members and being displaceable by means of a motorized drive between an open end position and a closed end position.
According to the invention, the motorized drive can be actuated to operate in a non-uniform mode in which the speed of displacement of the window glass is varied in a translocation phase after conclusion of a start-up phase. This is achieved preferably by means of an inventive motor control for an electric window-raising motor, which comprises a control module which drives the electric window-raising motor non-uniformly in the activated state. By virtue of the non-uniform movement of the window glass, the generation of noise during the displacement is considerably reduced. Alternatively, the non-uniform movement of the glass via the motorized drive can be produced in the non-uniform mode by means of a gear system.
Preferably, an electric motor is provided as the motorized drive in a movable window unit according to the invention. An electric motor offers the advantage of easy controllability. In a control system provided in such a case, the control module for the non-uniform mode of operation can be integrated in a common integrated circuit with a module for the short stroke movement of the glass for the opening and closing of the door.
According to a preferred embodiment of the invention, in the non-uniform mode, the motorized drive is switched back and forth between a first, upper speed of rotation and a second, lower speed of rotation. Such switching back and forth can be effected with simple means in terms of technical control.
As a preferred alternative to this switching back and forth between two speeds of rotation, one can, in accordance with a further preferred embodiment of the invention, arrange that the motorized drive comprises a preferably electronic drive control means which imposes on a basic speed of rotation of an electric motor a rotational component having substantially sinusoidal character. With such a drive control means the motor noises are reduced and the visual perception of the non-uniform motion of the window glass is made less noticeable.
Since it is conceivable that users of a movable window unit in accordance with the invention could misunderstand the non-uniform motion of the window glass as being an operational failure, there is provision for activating the non-uniform mode of operation only if an undesirable amount of noise is feared. In order to achieve this, the movable window unit can be provided with a sensor device which determines the moment of resistance which opposes the motorized drive during the displacement of the window glass. By evaluation of the measured values from this sensor device in an activating device the non-uniform mode of operation of the motorized drive can be activated.
If an electric motor is provided for the motorized drive, then preferably in order to determine the moment of resistance which opposes the electric motor during the displacement of the window glass, measuring transformers monitoring the power consumption of the electric motor are provided, the output signals from which are fed to an activating device which activates the non-uniform mode of operation.
Further advantageous features and embodiments of the invention are set out in the subsidiary claims as well as in the following description which is to be read in conjunction with the drawings.